This article compares the approach of the Court of Justice in the area of taxation with its general case law on restrictions on free movement. It is argued that the Court, while sometimes referring to the same concepts as in the field of regulatory barriers, is in practice employing a narrower test. The possible reasons for the comparatively cautious approach are analysed and the issue of double taxation is examined, with reference also to the US case law. Finally, the connections to larger questions concerning the nature of the single market and the roles of the Community institutions are noted.